I'm assuming they probably have a poor Account QS by now. I could maybe start a whole new account, but that seems like a nuisance. I can't image Google wants us creating new accounts every time one gets in a bad way. I may end up deleting everything they've done anyway, but in the short term, while I'm sorting things out and learning what they've done and what worked and what didn't, if I pause all their stuff while creating new stuff of my own, will I have to worry about all those paused campaigns affecting QS in the future, or are they taken out of the picture once paused?
I'm not entirely sure I described this well, but maybe someone will understand what I mean.
I know there is a belief that whole account carries some weight, aka QS. It makes sense to think that overall account QS (if something like that exists) can influence how your ad group or campaign will perform.
Now, if you think that active campaign #1 can affect active campaign #2 vs. paused/active, vs. deleted/active, I don’t think you should worry about that. If that is true, AdWords would be too vulnerable to negative tricks and shortcuts.
I believe that your best bet is to reorganize and focus on ad text/keywords groupings. That is at least what people have been saying when about improving quality score. Few keywords per ad group, matching ad text, and possibly landing page.
My idea is that regardless of account, Google has the data about how certain keywords relate to certain URLs, with or without having any advertising history. Then, there are some data in regards of specific account, mostly keyword history.
My point is that new account with same URL more or less would not help, so you should be good to go with existing one.
I hope I did not misunderstand your question.
